Response of blood pressure and cardiac myosin polymorphism to swimming training in the spontaneously hypertensive rat

1982 ◽  
Vol 60 (8) ◽  
pp. 1098-1103 ◽  
Author(s):  
Heinz Rupp ◽  
Ruthard Jacob
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Spontaneously Hypertensive Rat ◽  
Hypertensive Rats ◽  
Swimming Training ◽  
Myosin V ◽  
Spontaneously Hypertensive ◽  
Myosin Isoenzyme

Cardiac muscle can adapt to different functional demands, as evidenced by polymorphism of myosin. Pressure load in spontaneously hypertensive rats induced a shift of the myosin isoenzymes towards myosin V3 (18% V1, 27% V2, 55% V3) relative to normotensive Wistar rats (49% V1, 29% V2, 22% V3). A swimming routine with Wistar rats resulted in a shift towards myosin V1 (72% V1, 18% V2, 10% V3). The training effect is not restricted to normotensive rats, since spontaneously hypertensive rats subjected to the same swimming routine exhibited a myosin isoenzyme pattern (38% V1, 31% V2, 31% V3) approaching that of the sedentary Wistar rats. Swimming training can, therefore, prevent the myosin isoenzyme redistribution towards myosin V3 found in sedentary spontaneously hypertensive rats. Furthermore, systolic blood pressure was significantly reduced (130 ± 8 mmHg (1 mmHg = 133.322 Pa)) in the swim-trained compared with the sedentary spontaneously hypertensive rats (157 ± 12 mmHg). The training-induced changes in myosin polymorphism and systolic blood pressure are, at least partially, attributed to substantially normalized sympathetic activity. The functional relevance of swimming training in the spontaneously hypertensive rat is seen in the increased potential of coping with situations requiring fast contraction which may occur during sudden physical exertion or emotional stress.

Long-Term Fructose versus Corn Starch Feeding in the Spontaneously Hypertensive Rat

1995 ◽  
Vol 88 (6) ◽  
pp. 719-725 ◽  
Author(s):  
Margriet R. van der Schaaf ◽  
Jaap A. Joles ◽  
Arie van Tol ◽  
Hein A. Koomans
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Corn Starch ◽  
Spontaneously Hypertensive Rat ◽  
Glucose Load ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Hypertensive Rat

1. Fructose feeding, as opposed to vegetable starch feeding, has been shown to elevate blood pressure and to decrease insulin sensitivity in normotensive rats. The long-term relevance of this is unclear, and data in hypertensive strains are scarce. 2. We studied the effects of 27 weeks of a fructose-versus a corn-starch-enriched (69.5% w/w) diet in the spontaneously hypertensive rat. 3. In both dietary groups, blood pressure increased with ageing, with no apparent difference between the diets. The fructose-fed rats gained less weight. However, even selecting fructose-fed rats that matched the weight gain in the corn starch group, did not reveal a significant elevation of systolic blood pressure over time. 4. Extracellular fluid volume was comparable in fructose-fed and corn-starch-fed rats. No effects on creatinine clearance, proteinuria or renal histology were found. Fasting values of plasma triacylgycerols and cholesterol were increased mildly after 2 weeks on the fructose diet. However, fasting glucose and insulin measured after 2 weeks, and the response to an intraperitoneal glucose load, were no different. After 23 weeks of the diets, fasting values of plasma glucose, insulin, triacylglycerols and cholesterol did not differ. There were small differences in the response of plasma glucose levels to the intraperitoneal glucose load, but the area under the curve was not different. The baseline insulin resistance present in spontaneously hypertensive rats possibly blunts the metabolic response to dietary fructose. 5. After 27 weeks, the diets were switched in crossover design, and measurements were continued until 39 weeks. The fructose diet did not elevate systolic blood pressure in this follow-up experiment. 6. To summarize, long-term fructose versus corn starch feeding did not increase systolic blood pressure in spontaneously hypertensive rats. Metabolic variables were transiently affected and renal function was undisturbed. These findings suggest that long-term fructose feeding, compared with other dietary carbohydrates, is not specifically harmful in the spontaneously hypertensive rat.

Metformin decreases plasma insulin levels and systolic blood pressure in spontaneously hypertensive rats

1994 ◽  
Vol 267 (4) ◽  
pp. H1250-H1253 ◽  
Author(s):  
S. Verma ◽  
S. Bhanot ◽  
J. H. McNeill
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Plasma Insulin ◽  
Metformin Treatment ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Insulin Levels ◽  
Plasma Insulin Levels ◽  
Wistar Kyoto

To determine the relationship between hyperinsulinemia and hypertension in spontaneously hypertensive rats (SHR), the antihyperglycemic agent metformin was administered to SHR and their Wistar-Kyoto (WKY) controls, and its effects on plasma insulin levels and blood pressure were examined. Five-week-old rats were started on oral metformin treatment (350 mg.kg-1.day-1, which was gradually increased to 500 mg.kg-1.day-1 over a 2-wk period). Metformin treatment caused sustained decreases in plasma insulin levels in the SHR (27.1 +/- 2.3 vs. untreated SHR 53.5 +/- 2.7 microU/ml, P < 0.001) without having any effect in the WKY (30.7 +/- 2.2 vs. untreated WKY 37.8 +/- 1.6 microU/ml, P > 0.05). The treatment did not affect the plasma glucose levels in any group. Metformin treatment also attenuated the increase in systolic blood pressure in the SHR (157 +/- 6.0 vs. untreated SHR 196 +/- 9.0 mmHg, P < 0.001) but had no effect in the WKY (134 +/- 3 vs. untreated WKY 136 +/- 4 mmHg, P > 0.05). Furthermore, raising plasma insulin levels in the metformin-treated SHR to levels that existed in the untreated SHR reversed the effect of metformin on blood pressure (189 +/- 3 vs. untreated SHR 208 +/- 5.0 mmHg, P > 0.05). These findings suggest that either hyperinsulinemia may contribute toward the increase in blood pressure in the SHR or that the underlying mechanism is closely associated with the expression of both these disorders.

Effects of Chronic Administration of Sarpogrelate on Systolic Blood Pressure of Spontaneously Hypertensive Rats: Comparison with Quinapril

Pharmacology ◽  
2002 ◽  
Vol 64 (2) ◽  
pp. 71-75 ◽  
Author(s):  
Yuki Setoguchi ◽  
Toshio Ohnuki ◽  
Mamunur Rashid ◽  
Takashi Nakamura ◽  
Kaoru Hattori ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Systolic Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Chronic Administration ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

Effect of Curcuma Herbs on Vasomotion and Hemorheology in Spontaneously Hypertensive Rat

2005 ◽  
Vol 33 (03) ◽  
pp. 449-457 ◽  
Author(s):  
Hirozo Goto ◽  
Yohei Sasaki ◽  
Hirotoshi Fushimi ◽  
Naotoshi Shibahara ◽  
Yutaka Shimada ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Spontaneously Hypertensive Rat ◽  
Radical Scavenging ◽  
Male Rats ◽  
Control Group ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Scavenging Effect ◽  
Low Shear Stress

Curcuma herbs have a vasodilator effect. The effects of C. longa, which induces only endothelium-independent vasodilatation, and C. zedoaria, which induces both endothelium-dependent and -independent vasodilatation, were studied on vasomotion and hemorheology in spontaneously hypertensive rats. Spontaneously hypertensive eight-week-old male rats were assigned to five groups. For 12 weeks, the control group received standard chow. The 3%CL (C. longa) group received standard chow containing 3% (wt/wt) C. longa. The 1%CZ and 3%CZ (C. zedoaria) groups received standard chow containing 1% and 3% (wt/wt) C. zedoaria, respectively. The captoril group received standard chow and 100 mg/kg/day of captoril in drinking water. Blood pressure, vasomotion, hemorheology, etc. were examined. Systolic blood pressure of the 3%CZ and captoril groups decreased significantly as compared to the control group. Acetylcholine-induced endothelium-dependent relaxations of the 3%CZ and captoril groups were increased to a greater degree, significantly, than the control group. When testing xanthine oxidase-induced contraction, the 3%CZ group was significantly decreased as compared to the control group. Low shear stress of whole blood viscosity showed the 3%CL and 3%CZ groups to be decreased significantly compared to the control group. Thus, Curcuma herbs have hypotensive and protective effect on the endothelium in spontaneously hypertensive rats. Especially, C. zedoaria is more effective than C.longa, and its mechanism is thought to be related to a radical scavenging effect and improvement of hemorheology.

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